The project will demonstrate the feasibility in a variety of ambulatory care sites, of a simple form of quality assessment: medical records audit using explicit process criteria for items believed to be strongly linked to improving patient outcomes. The audit will be specifically designed to use only routinely available sources of data, in order to ensure that it is likely to be readily transferable for use in any ambulatory care site. The project will assess the effectiveness of the use of this mode of audit in a classical cyclic quality assurance program which attempts to change provider behavior toward compliance with criteria via a "feedback loop." The incremental impact of several component steps of this quality assurance cycle will be separately assessed by repeated audits before and after intervention. The interventions thus studied will be: announcement of the topic, publication of criteria, feedback of audit results, administrative changes in response to audit results, and lapse of time without further intervention. The research design for this assessment of effectiveness will be a controlled trial, with 2 stratified groups of providers randomly assigned to experimental or control status for one or two sets of audit topics. Each subject group will be audited for both sets of topics, but for "experimental" topics will be exposed to the interventions listed above and for "control" topics will not be exposed to any of these interventions. The project will collect retrospective baseline data for a 1 year pre-project period and will stagger the launching of successive audit topics through the quality assurance cycle over time. These features will enable an assessment of the Hawthorne effect by a time series design. An assessment of the cost for the routine use of this mode of audit will also be made, subject to the limitations of routinely available data sources. Questionnaires will be sent to personnel affected by the audit project in an attempt to discover any unexpected untoward consequences of the audit project, which will be documented insofar as routinely available data sources permit.